<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .zhong{
            display: flex;
        }
        .left{
            height: 800px;
            width: 300px;
            background-color: yellow;
        }
        .top{
            width: 100vw;
            height: 50px;
            background-color: red;
        }
        .bottom{
            width: 100vw;
            height: 50px;
            background-color: rgb(30, 255, 0);
        }
        .center{
            flex: 2;
            width: 400px;
            height: 800px;
            background-color: aqua;
        }
        .right{
            height: 800px;
            width: 300px;
            background-color: pink;
        }
    </style>
</head>
<body>
<div class="all">
    <div class="top"></div>
    <div class="zhong">
        <div class="left"></div>
        <div class="center"></div>
        <div class="right"></div>
    </div>
    <div class="bottom"></div>
</div>
</body>
</html>